This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A129220 #16 Feb 16 2025 08:33:05 %S A129220 4,14,194,788,701,119,1877,240,282,1736 %N A129220 Residues of the Lucas - Lehmer primality test for M(11) = 2047. %C A129220 Since a(9) > 0, M(11) is composite. In fact, 2047 = 23 * 89 %H A129220 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Lucas-LehmerTest.html">Lucas Lehmer Test</a>. %H A129220 Wikipedia, <a href="https://en.wikipedia.org/wiki/Lucas-Lehmer_primality_test">Lucas Lehmer Primality Test</a>. %F A129220 a(0) = 4; a(n) = a(n-1)^2-2 mod 2^p-1. Last term: a(p-2). %e A129220 a(9) = a(8)^2 - 2 mod 2047 = 282^2 - 2 mod 2047 = 1736. %Y A129220 Cf. A095847, A003010, A129218, A129219, A129221, A129222, A129223, A129224, A129225, A129226, A001348. %K A129220 fini,full,nonn %O A129220 0,1 %A A129220 _Sergio Pimentel_, Apr 05 2007 %E A129220 Offset corrected by _Nathaniel Johnston_, May 31 2011